Electronic circuits are ubiquitous in modern society and may be found in such diverse applications as computers, combustion engines and toys. To reduce the size and cost of electronic circuits, modern technology has created the printed circuit board. A printed circuit board is a rigid board made of an insulating material, for example plastic, to which the elements of a circuit, for example capacitors, resistors, transistors, inductors, etc. are attached. Interconnections between the circuit elements are made by lines of conductive material that are "printed" on the board.
The printed circuit board allows a large number of circuits to be manufactured reliably and at low cost due to the fact that the intricate connections between circuit elements are already provided on the board. Moreover, the connections provided on the circuit board require less space than if the circuit elements were otherwise wired together, particularly if the circuit is fairly complex.
It may be realized that the reduction in required space provided by the printed circuit board could be increased if both sides of the printed circuit board are used. In other words, if the necessary electronic circuits are disposed, not just on the upper surface of the printed circuit board, but on both the upper and lower surfaces, the circuit board may be reduced in size by as much as half. Alternatively, more circuitry may be provided on a particular circuit board if both sides of the board are used to carry circuitry.
However, a problem arises in providing circuitry on both sides of the printed circuit board. This problem is the difficulty of easily and inexpensively connecting the circuits on the two opposite surfaces of the circuit board to each other. Connections between the two circuits may be needed at one, several or many points to provide the optimal design for the circuit as a whole.
In the past, such connections have been provided by forming plated through-holes in the printed circuit boards. However, this approach is time-consuming and costly.
Accordingly, there is a need in the art for a method and device that easily and inexpensively provides a reliable electrical connection between circuits on two opposite surfaces of a printed circuit board.